ASP.Net Session.Timeout - Is StateServer and Programmatic Session.Timeout Good Enough?

Question

Reading around, it looks like changing asp.net session time when using the InProc model requires two changes...

1. web.config - Application Pool Idle
2. Timeout - Seems you should set this >= Session.Timeout

I gathered this from reading http://asp-net.vexedlogic.com/2012/05/23/aspasp-net-session-timeout-how-do-i-change-it/.

So, if I don't have the luxury of changing timeouts on application pools, I'm wondering if I change to use StateServer and then programmatically set Session.Timeout as described in the article above, do I need to worry about what web.config @timeout and application pool idle settings are set at? Will my two actions take care of everything?

If it does take care of it, I guess the next question is whether or not anyone knows how performance compares from InProc vs StateServer.

Thanks in advance.

Answer 1

From my understanding, if you switch from in-proc to state server the idle timeout (in IIS) setting won't have an effect on your session state timeout.

There will still be worker processes that may be terminated in the application pool if there is no activity (if the idle timeout is passed) but the session state (i.e. the user session and application session values) will be maintained beyond this. Your session timeout should just be controlled by the timeout value set in the configuration (from here) i.e.

<configuration>
  <system.web>
    <sessionState mode="StateServer"
      stateConnectionString="tcpip=SampleStateServer:42424"
      cookieless="false"
      timeout="20"/>
  </system.web>
</configuration>

Inproc is faster than StateServer as your session data needs to be serialised / deserialised when it's stored. It may also be stored on a separate machine which may introduce some latency. But of course there are the advantages of State Server i.e. Session state persistence between application restarts (app pool recycling), state can be shared across multiple servers in a web-farm.

This question also discusses pros and cons of using the State Server mode.